Abstract

One of the primary goals of martian studies is to determine if there ever was, or could still be, life on Mars. Many techniques for achieving this goal have been tried, and very many more have been proposed. However, there are flaws in virtually all of them. This paper initially illustrates the validity or otherwise of existing proposals for finding extant or extinct biological activity on Mars, and suggests an alternative method. It is argued that a class of bacterial membrane-lipid components known as hopanoids may provide a more potent and perspicuously biological signature, both on Mars and on other potentially life-bearing bodies. A sample of modern sediment from a river bed was analysed by GC-MS and shown to contain biohopanoid components that could be used to identify criteria for the unambiguous detection of these compounds by an experiment suitable for delivery to Mars on a lander. It is concluded that the wholly unambiguous detection of past or present biological activity on Mars (or any other planetary body) is likely to require the presence of human beings in situ.

Type:

Thesis
(Masters)

Title:

On the problem of ambiguity in extraterrestrial biomarkers: implications for Mars